Methods and systems for protecting computing resources

ABSTRACT

Some embodiments of the present invention include a method for controlling requests to be transmitted to a server computing system. The method generating, by a first requester, a request to be transmitted to a first server computing system, the first requester being part of a first group of requesters, each of the requesters in the first group of requesters is configured to access an indicator to determine whether the first server computing system is ready to receive its request, the indicator being set or reset at least based on a response received from the first server computing system, the indicator stored in a memory device associated with a second server computing system; and based on the indicator indicating that the first server computing system is not ready, delaying from transmitting, by the first requester, the request to the first server computing system.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

TECHNICAL FIELD

The present disclosure relates generally to data processing and morespecifically relates to controlling requests transmitted to a servercomputing system.

BACKGROUND

The subject matter discussed in the background section should not beassumed to be prior art merely as a result of its mention in thebackground section. Similarly, a problem mentioned in the backgroundsection or associated with the subject matter of the background sectionshould not be assumed to have been previously recognized in the priorart. The subject matter in the background section merely representsdifferent approaches, which in and of themselves may also be inventions.

Server computing systems may receive and process many requests from manyrequesters. As the number of requests increases, the performance of theserver may be affected. For example, the time it takes for a servercomputing system to provide a response to a request may be slower. Whenthere are thousands of requests or when there are many requests thatrequire intensive processing by the server computing systems, theperformance impact is experienced by all of the requesters. It may beuseful to control the number of requests to optimize the performance ofthe server computing system.

BRIEF SUMMARY

For some embodiments, methods and systems for controlling requeststransmitted to a server computing system may include generating, by afirst requester, a request to be transmitted to a first server computingsystem, the first requester being part of a first group of requesters,each of the requesters in the first group of requesters is configured toaccess an indicator to determine whether the first server computingsystem is ready to receive its request, the indicator being set or resetat least based on a response received from the first server computingsystem, the indicator stored in a memory device associated with a secondserver computing system; and based on the indicator indicating that thefirst server computing system is not ready, delaying from transmitting,by the first requester, the request to the first server computingsystem. Other aspects and advantages of the present invention can beseen on review of the drawings, the detailed description and the claims,which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

The included drawings are for illustrative purposes and serve only toprovide examples of possible structures and process steps for thedisclosed techniques. These drawings in no way limit any changes in formand detail that may be made to embodiments by one skilled in the artwithout departing from the spirit and scope of the disclosure.

FIG. 1 shows a diagram of an example computing system that may be usedwith some embodiments.

FIG. 2 shows a diagram of an example network environment that may beused with some embodiments.

FIG. 3 shows an example diagram of multiple requests received by thedata source server, in accordance with some embodiments.

FIG. 4 is a diagram that shows an example shared memory that may be usedby requesters to verify the availability of a data source server, inaccordance with some embodiments.

FIG. 5 is a diagram that shows an example scenario of using a sharedmemory to delay transmitting requests associated with low priorityservices when the data source server is busy, in accordance with someembodiments.

FIG. 6 is a diagram that shows an example scenario of using a sharedmemory to transmit requests associated with low priority services whenthe data source server is not busy, in accordance with some embodiments.

FIG. 7A shows a flowchart of an example process for delaying fromtransmitting requests to a data source server to protect serverresources, in accordance with some embodiments.

FIG. 7B shows a flowchart of an example process for keeping track of theavailability of a data source server, in accordance with someembodiments.

FIG. 8A shows a system diagram illustrating architectural components ofan applicable environment, in accordance with some embodiments.

FIG. 8B shows a system diagram further illustrating architecturalcomponents of an applicable environment, in accordance with someembodiments.

FIG. 9 shows a system diagram illustrating the architecture of amulti-tenant database environment, in accordance with some embodiments.

FIG. 10 shows a system diagram further illustrating the architecture ofa multi-tenant database environment, in accordance with someembodiments.

DETAILED DESCRIPTION

Applications of systems and methods for controlling requests transmittedto a server computing system are disclosed. The requests may begenerated by a plurality of requesters. The requests may be of differenttypes. Depending on a type of a request and availability of resources ofthe server computing system, a request may or may not be serviced by theserver computing system. To control the requests transmitted to theserver computing system, the availability of the server computing systemmay first be verified before transmitting a request to the servercomputing system. When the server computing system is busy, thetransmission of the requests may be backed off.

The systems and methods will be described with reference to exampleembodiments. These examples are being provided solely to add context andaid in the understanding of the present disclosure. It will thus beapparent to one skilled in the art that the techniques described hereinmay be practiced without some or all of these specific details. In otherinstances, well known process steps have not been described in detail inorder to avoid unnecessarily obscuring the present disclosure. Otherapplications are possible, such that the following examples should notbe taken as definitive or limiting either in scope or setting.

In the following detailed description, references are made to theaccompanying drawings, which form a part of the description and in whichare shown, by way of illustration, specific embodiments. Although theseembodiments are described in sufficient detail to enable one skilled inthe art to practice the disclosure, it is understood that these examplesare not limiting, such that other embodiments may be used and changesmay be made without departing from the spirit and scope of thedisclosure.

As used herein, the term “multi-tenant database system” refers to thosesystems in which various elements of hardware and software of thedatabase system may be shared by one or more customers. For example, agiven application server may simultaneously process requests for a greatnumber of customers, and a given database table may store rows for apotentially much greater number of customers.

The described subject matter may be implemented in the context of anycomputer-implemented system, such as a software-based system, a databasesystem, a multi-tenant environment, or the like. Moreover, the describedsubject matter may be implemented in connection with two or moreseparate and distinct computer-implemented systems that cooperate andcommunicate with one another. One or more embodiments may be implementedin numerous ways, including as a process, an apparatus, a system, adevice, a method, a computer readable medium such as a computer readablestorage medium containing computer readable instructions or computerprogram code, or as a computer program product comprising a computerusable medium having a computer readable program code embodied therein.

The disclosed embodiments may include systems and methods forcontrolling requests to be transmitted to a server computing system andmay include generating, by a first requester, a request to betransmitted to a first server computing system, the first requesterbeing part of a first group of requesters, each of the requesters in thefirst group of requesters is configured to access an indicator todetermine whether the first server computing system is ready to receiveits request, the indicator being set or reset at least based on aresponse received from the first server computing system, the indicatorstored in a memory device associated with a second server computingsystem; and based on the indicator indicating that the first servercomputing system is not ready, delaying from transmitting, by the firstrequester, the request to the first server computing system.

The disclosed embodiments may include an apparatus for controllingrequests to be transmitted to a server computing system and include aprocessor, and one or more stored sequences of instructions which, whenexecuted by the processor, cause the processor to generate a request tobe transmitted to a first server computing system, the first requesterbeing part of a first group of requesters, each of the requesters in thefirst group of requesters is configured to access an indicator todetermine whether the first server computing system is ready to receiveits request, the indicator being set or reset at least based on aresponse received from the first server computing system, the indicatorstored in a memory device associated with a second server computingsystem; and based on the indicator indicating that the first servercomputing system is not ready, delay from transmitting the request tothe first server computing system.

The disclosed embodiments may include a machine-readable medium carryingone or more sequences of instructions for controlling requeststransmitted to a server computing system, which instructions, whenexecuted by one or more processors, may cause the one or more processorsto generate a request to be transmitted to a first server computingsystem, the first requester being part of a first group of requesters,each of the requesters in the first group of requesters is configured toaccess an indicator to determine whether the first server computingsystem is ready to receive its request, the indicator being set or resetat least based on a response received from the first server computingsystem, the indicator stored in a memory device associated with a secondserver computing system; and based on the indicator indicating that thefirst server computing system is not ready, delay from transmitting therequest to the first server computing system.

While one or more implementations and techniques are described withreference to an embodiment in which the transmitting of requests to aserver computing system is controlled is implemented in a system havingan application server providing a front end for an on-demand databaseservice capable of supporting multiple tenants, the one or moreimplementations and techniques are not limited to multi-tenant databasesnor deployment on application servers. Embodiments may be practicedusing other database architectures, i.e., ORACLE®, DB2® by IBM and thelike without departing from the scope of the embodiments claimed.

Any of the above embodiments may be used alone or together with oneanother in any combination. The one or more implementations encompassedwithin this specification may also include embodiments that are onlypartially mentioned or alluded to or are not mentioned or alluded to atall in this brief summary or in the abstract. Although variousembodiments may have been motivated by various deficiencies with theprior art, which may be discussed or alluded to in one or more places inthe specification, the embodiments do not necessarily address any ofthese deficiencies. In other words, different embodiments may addressdifferent deficiencies that may be discussed in the specification. Someembodiments may only partially address some deficiencies or just onedeficiency that may be discussed in the specification, and someembodiments may not address any of these deficiencies.

The described subject matter may be implemented in the context of anycomputer-implemented system, such as a software-based system, a databasesystem, a multi-tenant environment, or the like. Moreover, the describedsubject matter may be implemented in connection with two or moreseparate and distinct computer-implemented systems that cooperate andcommunicate with one another. One or more implementations may beimplemented in numerous ways, including as a process, an apparatus, asystem, a device, a method, a computer readable medium such as acomputer readable storage medium containing computer readableinstructions or computer program code, or as a computer program productcomprising a computer usable medium having a computer readable programcode embodied therein.

FIG. 1 is a diagram of an example computing system that may be used withsome embodiments of the present invention. The computing system 102 maybe used by a user to log in to an application and initiate a request tobe transmitted to a server computing system to be processed by theserver computing system. For example, the request may include a requestto assess user's data. The request may be sent to a server computingsystem that is configured to assess the user's data using, for example,one or more data sources. The server computing system may respond to therequest by providing an assessment of the user's data. The assessmentmay include a sample of what an enhanced use's data may look like. Forsome embodiments, the server computing system may be associated with amulti-tenant database environment. For example, the multi-tenantdatabase environment may be associated with the services provided bySalesforce.com®.

The computing system 102 is only one example of a suitable computingsystem, such as a mobile computing system, and is not intended tosuggest any limitation as to the scope of use or functionality of thedesign. Neither should the computing system 102 be interpreted as havingany dependency or requirement relating to any one or combination ofcomponents illustrated. The design is operational with numerous othergeneral purpose or special purpose computing systems. Examples ofwell-known computing systems, environments, and/or configurations thatmay be suitable for use with the design include, but are not limited to,personal computers, server computers, hand-held or laptop devices,multiprocessor systems, microprocessor-based systems, set top boxes,programmable consumer electronics, mini-computers, mainframe computers,distributed computing environments that include any of the above systemsor devices, and the like. For example, the computing system 102 may beimplemented as a mobile computing system such as one that is configuredto run with an operating system (e.g., iOS) developed by Apple Inc. ofCupertino, Calif. or an operating system (e.g., Android) that isdeveloped by Google Inc. of Mountain View, Calif.

Some embodiments of the present invention may be described in thegeneral context of computing system executable instructions, such asprogram modules, being executed by a computer. Generally, programmodules include routines, programs, objects, components, datastructures, etc. that performs particular tasks or implement particularabstract data types. Those skilled in the art can implement thedescription and/or figures herein as computer-executable instructions,which can be embodied on any form of computing machine program productdiscussed below.

Some embodiments of the present invention may also be practiced indistributed computing environments where tasks are performed by remoteprocessing devices that are linked through a communications network. Ina distributed computing environment, program modules may be located inboth local and remote computer storage media including memory storagedevices.

Referring to FIG. 1, the computing system 102 may include, but are notlimited to, a processing unit 120 having one or more processing cores, asystem memory 130, and a system bus 121 that couples various systemcomponents including the system memory 130 to the processing unit 120.The system bus 121 may be any of several types of bus structuresincluding a memory bus or memory controller, a peripheral bus, and alocal bus using any of a variety of bus architectures. By way ofexample, and not limitation, such architectures include IndustryStandard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus,Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA)locale bus, and Peripheral Component Interconnect (PCI) bus also knownas Mezzanine bus.

The computing system 102 typically includes a variety of computerprogram product. Computer program product can be any available mediathat can be accessed by computing system 102 and includes both volatileand nonvolatile media, removable and non-removable media. By way ofexample, and not limitation, computer program product may storeinformation such as computer readable instructions, data structures,program modules or other data. Computer storage media include, but arenot limited to, RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disks (DVD) or other optical diskstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, or any other medium which can be used tostore the desired information and which can be accessed by computingsystem 102. Communication media typically embodies computer readableinstructions, data structures, or program modules.

The system memory 130 may include computer storage media in the form ofvolatile and/or nonvolatile memory such as read only memory (ROM) 131and random access memory (RAM) 132. A basic input/output system (BIOS)133, containing the basic routines that help to transfer informationbetween elements within computing system 102, such as during start-up,is typically stored in ROM 131. RAM 132 typically contains data and/orprogram modules that are immediately accessible to and/or presentlybeing operated on by processing unit 120. By way of example, and notlimitation, FIG. 1 also illustrates operating system 134, applicationprograms 135, other program modules 136, and program data 137.

The computing system 102 may also include other removable/non-removablevolatile/nonvolatile computer storage media. By way of example only,FIG. 1 also illustrates a hard disk drive 141 that reads from or writesto non-removable, nonvolatile magnetic media, a magnetic disk drive 151that reads from or writes to a removable, nonvolatile magnetic disk 152,and an optical disk drive 155 that reads from or writes to a removable,nonvolatile optical disk 156 such as, for example, a CD ROM or otheroptical media. Other removable/non-removable, volatile/nonvolatilecomputer storage media that can be used in the exemplary operatingenvironment include, but are not limited to, USB drives and devices,magnetic tape cassettes, flash memory cards, digital versatile disks,digital video tape, solid state RAM, solid state ROM, and the like. Thehard disk drive 141 is typically connected to the system bus 121 througha non-removable memory interface such as interface 140, and magneticdisk drive 151 and optical disk drive 155 are typically connected to thesystem bus 121 by a removable memory interface, such as interface 150.

The drives and their associated computer storage media discussed aboveand illustrated in FIG. 1, provide storage of computer readableinstructions, data structures, program modules and other data for thecomputing system 102. In FIG. 1, for example, hard disk drive 141 isillustrated as storing operating system 144, application programs 145,other program modules 146, and program data 147. Note that thesecomponents can either be the same as or different from operating system134, application programs 135, other program modules 136, and programdata 137. The operating system 144, the application programs 145, theother program modules 146, and the program data 147 are given differentnumeric identification here to illustrate that, at a minimum, they aredifferent copies.

A user may enter commands and information into the computing system 102through input devices such as a keyboard 162, a microphone 163, and apointing device 161, such as a mouse, trackball or touch pad or touchscreen. Other input devices (not shown) may include a joystick, gamepad, scanner, or the like. These and other input devices are oftenconnected to the processing unit 120 through a user input interface 160that is coupled with the system bus 121, but may be connected by otherinterface and bus structures, such as a parallel port, game port or auniversal serial bus (USB). A monitor 191 or other type of displaydevice is also connected to the system bus 121 via an interface, such asa video interface 190. In addition to the monitor, computers may alsoinclude other peripheral output devices such as speakers 197 and printer196, which may be connected through an output peripheral interface 190.

The computing system 102 may operate in a networked environment usinglogical connections to one or more remote computers, such as a remotecomputer 180. The remote computer 180 may be a personal computer, ahand-held device, a server, a router, a network PC, a peer device orother common network node, and typically includes many or all of theelements described above relative to the computing system 102. Thelogical connections depicted in

FIG. 1 includes a local area network (LAN) 171 and a wide area network(WAN) 173, but may also include other networks. Such networkingenvironments are commonplace in offices, enterprise-wide computernetworks, intranets and the Internet.

When used in a LAN networking environment, the computing system 102 maybe connected to the LAN 171 through a network interface or adapter 170.When used in a WAN networking environment, the computing system 102typically includes a modem 172 or other means for establishingcommunications over the WAN 173, such as the Internet. The modem 172,which may be internal or external, may be connected to the system bus121 via the user-input interface 160, or other appropriate mechanism. Ina networked environment, program modules depicted relative to thecomputing system 102, or portions thereof, may be stored in a remotememory storage device. By way of example, and not limitation, FIG. 1illustrates remote application programs 185 as residing on remotecomputer 180. It will be appreciated that the network connections shownare exemplary and other means of establishing a communications linkbetween the computers may be used.

It should be noted that some embodiments of the present invention may becarried out on a computing system such as that described with respect toFIG. 1. However, some embodiments of the present invention may becarried out on a server, a computer devoted to message handling,handheld devices, or on a distributed system in which different portionsof the present design may be carried out on different parts of thedistributed computing system.

Another device that may be coupled with the system bus 121 is a powersupply such as a battery or a Direct Current (DC) power supply) andAlternating Current (AC) adapter circuit. The DC power supply may be abattery, a fuel cell, or similar DC power source needs to be rechargedon a periodic basis. The communication module (or modem) 172 may employa Wireless Application Protocol (WAP) to establish a wirelesscommunication channel. The communication module 172 may implement awireless networking standard such as Institute of Electrical andElectronics Engineers (IEEE) 802.11 standard, IEEE std. 802.11-1999,published by IEEE in 1999.

Examples of mobile computing systems may be a laptop computer, a tabletcomputer, a Netbook, a smart phone, a personal digital assistant, orother similar device with on board processing power and wirelesscommunications ability that is powered by a Direct Current (DC) powersource that supplies DC voltage to the mobile computing system and thatis solely within the mobile computing system and needs to be rechargedon a periodic basis, such as a fuel cell or a battery.

FIG. 2 shows a diagram of an example network environment that may beused with some embodiments of the present invention. Network environment200 includes user computing systems 290, 291 and 292. One or more of theuser computing systems 290, 291 and 292 may be a mobile computingsystem. The user computing systems 290, 291 and 292 may be connected tothe network 250 via a cellular connection or via a Wi-Fi router (notshown). The network 250 may be the Internet. The user computing systems290, 291 and 292 may be coupled with server computing system 255 via thenetwork 250.

Each of the user computing systems 290, 291 and 292 may include arespective application module 208, 214 and 216. A user may use thecomputing system 290 and the application module 208 to connect to andcommunicate with the server computing system 255 and log intoapplication 257 (e.g., a Salesforce.com® application). For example, theuser may log into the application 257 to initiate a request to assessthe user's data. The server computing system 255 may be coupled withdatabase 270. For example, the database 270 may be configured to storethe user's data. The server computing system 255 may be associated withan entity (e.g., Salesforce.com®).

For some embodiments, the server computing system 255 may be coupledwith another server computing system 295 (referred to herein as datasource server 295). The data source server 295 may be coupled with adatabase 296 configured to store data associated with several differentdata sources. For example, a data source may be associated with a dataprovider specializing in data relating to a certain industry segment.One example of such data provider is Dunn & Bradstreet providing companyprofiles.

For some embodiment, when a user generates a request to assess a user'sdata, the request and the user's data may be transmitted from the servercomputing system 255 to the data source server 295 for assessment. Forsome embodiments, when a user generates a request to enhance the user'sdata, the request and the user's data may be transmitted from the servercomputing system 255 to the data source server 295 for enhancement. Forsome embodiments, a request for data assessment may be considered arequest for low priority service comparing to a request for dataenhancement because a data assessment request may be associated with afree service whereas a data enhancement request may be associated with apaid service.

FIG. 3 shows an example diagram of multiple requests received by thedata source server, in accordance with some embodiments. Diagram 300 isshown to include three requesters 390, 391 and 392 corresponding to usercomputing systems 290, 291 and 292. In this example, three requests390A, 391A and 392A are transmitted to the data source server 295. Therequests 390A and 391A may be associated with a low priority service,and the request 392A may be associated with a high priority service. Allthree requests are received and processed by the data source server 295.When the number of requests is high and the data source server 295 isbusy, the response times for the responses 390B, 391B and 392B may beslow. It may be possible that, when the data source server 295 is busy,it may be configured to send negative responses to the requests for lowpriority service to indicate that the data source server 295 is busy,such as shown in FIG. 3. However, when the number of requests similar tothe requests 390A and 391A is high, transmitting a negative response toevery such request may waste the available resources that could havebeen used to more effective process requests associated with a highpriority service, such as the request 392A.

FIG. 4 is a diagram that shows an example shared memory that may be usedby requesters to verify the availability of a data source server, inaccordance with some embodiments. For some embodiments, shared memory420 may include an indicator 405 to indicate the availability of thedata source server 295. The indicator 405 may be set (e.g., indicator=1)to indicate that the data source server 295 is busy and not available toreceive requests, or the indicator may be reset (e.g., indicator=0) toindicate that the data source server 295 is available to receiverequests. The shared memory 420 may be configured to be accessible bythe requesters that are associated with the low priority service, suchas the requesters 390 and 391. Initially, the indicator 405 may be resetto indicate that the data source server 295 is not busy. For someembodiments, the shared memory 420 may be located locally and separatelyfrom the data source server 295 such that accessing the shared memory420 may not utilize any resources of the data source server 295. Forsome embodiments, the shared memory 420 may be implemented using cachememory and may reside in the server computing system 255 (shown in FIG.2) or in a cache system (not shown) coupled to the server computingsystem 255.

For some embodiments, prior to sending a request to the data sourceserver 295, a requester may check the indicator 405 for the status ofthe data source server 295. For example, once the requester 390 checksthe indicator 405 and confirms that the data source server 295 isavailable (path 450), the requester 390 may cause the request 490A to betransmitted to the data source server 295. If the data source server 295is busy, it may transmit a response 490B to the requester 390 toindicate that it is busy. This may be implemented by, for example,setting a status bit in a http header of the response. For someembodiments, upon receiving the response and verifying that the datasource server 295 is busy, the requester 390 may set the indicator 405(path 490C). At a subsequent time, the requester 391 may check theindicator 405 for the status of the data source server 295 beforetransmitting its request. Upon determining that the indicator 405 isset, the requester 391 may delay from transmitting its request to thedata source server 295, thus protecting the data source server 295 fromwasting its resources from having to respond to the requester 391.

For some embodiments, the indicator 405 may be set when an expectedresponse is not received from the data source server 295 after a periodof time. For example, the indicator 405 may be set by the requester 390when an expected response is not received within 2 minutes. For someembodiments, the indicator 405 may be automatically reset afterexpiration of a reset period. For example, a reset period may be 10minutes. It may be possible that, even with the indicator 405 beingreset, the data source server 295 may still be busy. As such, a requesttransmitted to the data source server 295 may still get a responseindicating that the data source server 295 is busy. In that situation,the indicator 405 may again be set to delay further requests from beingtransmitted to the data source server 295. It may be noted that thechecking of the indicator 405 may only be necessary for the requestersassociated with the low priority service (e.g., free service). In thisexample, since the request 392A from the requester 392 is associatedwith a high priority service (e.g., paid service), the request 392A istransmitted to the data source server 295 regardless of setting of theindicator 405.

FIG. 5 is a diagram that shows an example scenario of using a sharedmemory to delay requests associated with low priority services when aserver is busy, in accordance with some embodiments. In this example,the indicator 405 is set to indicate that the data source server 295 isbusy. Prior to transmitting a request to the data source server 295, therequester 390 checks the indicator 405 (path 550), verifies that thedata source server 295 is busy, and backs off from transmitting anyrequests to the data source server 295. Similarly, the requester 391also checks the indicator 405 (path 560) and backs off from transmittingany requests to the data source server 295. Since the request 592A fromthe requester 392 is associated with a high priority service, it istransmitted to the data source server 295 regardless of the value of theindicator 405.

FIG. 6 is a diagram that shows an example scenario of using a sharedmemory to transmit requests associated with low priority services when aserver is not busy, in accordance with some embodiments. In thisexample, the indicator 405 is reset to indicate that the data sourceserver 295 is not busy. Prior to transmitting a request to the datasource server 295, the requester 390 checks the indicator 405 (path650), verifies that the data source server 295 is not busy, andtransmits the request 690A to the data source server 295. A response690B is transmitted in return. In this example, the response 690B doesnot include information indicating that the data source server 295 isbusy, so the indicator 405 is not set. Similarly, the requester 391 alsochecks the indicator 405 (path 660), verifies that the data sourceserver 295 is not busy, and transmits the request 691A to the datasource server 295. A response 691B is transmitted in return. In thisexample, the response 691B does not include information indicating thatthe data source server 295 is busy, so the indicator 405 is not set.Since the request 692A and the response 692B are associated with a highpriority service, they are processed regardless of the value of theindicator 405.

It may be noted that the availability of the data source server 295 maychange continuously depending on how much processing it has to performto service the requests it receives. Thus, it may be possible for thedata source server 295 to indicate in a response that it is busy at timet1, but the data source server 295 may become less busy or availableimmediately shortly after at time t2. For example, when the indicator405 indicates that data source server 295 is not busy, two requests fromdifferent requesters are transmitted to the data source server 295. Aresponse to the first request received at time t1 may indicate that thedata source server 295 is busy causing the indicator 405 to be set andthe first requester to delay from transmitting further requests.Normally, this would mean the first requester has to wait until theindicator 405 is automatically reset based on the expiration of thereset period. However, when a response to the second request is receivedat time t2 and it indicates that the data source server 295 is nowavailable, the indicator 405 may be reset by the second requester priorto the expiration of the reset period. For some embodiments, a requestermay periodically check the indicator 405 to verify the status of thedata source server even before expiration of the reset period. For someembodiments, the period of checking may vary exponentially. For example,a requester may first check after 4 seconds, then after 10 seconds, thenafter 25 seconds, etc.

FIG. 7A shows a flowchart of an example process for delaying fromtransmitting requests to a data source server to protect serverresources, in accordance with some embodiments. The example process 700may be used by requesters to request for low priority services from thedata source server 295. At block 705, a request may be generated. Priorto transmitting the request, the server availability status may bedetermined, as shown in block 710. This determination may be performedby accessing the shared memory 420 and indicator 405 (shown in FIGS.4-6) associated with, for example, the server computing system 255(shown in FIG. 2). By accessing the shared memory 420 associated withthe server computing system 255, no communication may be required withthe data source server 295 to verify its availability beforetransmitting the request. If the data source server 295 is determined tobe ready (or not busy), the request may then be transmitted to the datasource server 295, as shown in block 715. If the data source server 295is determined to be not ready (or busy), the requester may delay for adelay period before again checking the indicator 405 to determinewhether the data source server 295 is busy. For some embodiments, whenthe indicator 405 is not configured to be reset automatically, therequestor may delay for time “t” and then directly make another requestto the data source server without accessing the shared memory 420 andindicator 405, and then update the indicator 405 after getting aresponse from the data source server. When the indicator 405 isconfigured to be reset automatically after a reset period “n”, arequestor accessing the indicator 405 at time “n+1” will realize thatthe indicator 405 is reset (indicating the data source server is notbusy) and subsequently transmit a request to the data source server.Although not shown, it may be anticipated that the data source server295 will eventually become ready to receive the requests, thus avoidingan infinite loop of checking the indicator 405.

FIG. 7B shows a flowchart of an example process for keeping track of theavailability of a server to control transmitting the requests, inaccordance with some embodiments. The example process 750 may be used byrequesters to check the availability of the data source server 295 whenthe requests are for low priority services. At block 755, a response isreceived from the data source server 295. The response may includeinformation to indicate whether the data source server 295 is ready toreceive further requests. At block 760, the response is examined todetermine whether the data source server 295 is ready. This may include,for example, examining an http header of the response. If the datasource server 295 is not ready, the indicator 495 stored in the sharedmemory 420 associated with the server computing system 255 may be set,as shown in block 765. If the data source server 295 is ready, theindicator 405 may be reset, as shown in block 770.

FIG. 8A shows a system diagram 800 illustrating architectural componentsof an on-demand service environment, in accordance with someembodiments. A client machine located in the cloud 804 (or Internet) maycommunicate with the on-demand service environment via one or more edgerouters 808 and 812. The edge routers may communicate with one or morecore switches 820 and 824 via firewall 816. The core switches maycommunicate with a load balancer 828, which may distribute server loadover different pods, such as the pods 840 and 844. The pods 840 and 844,which may each include one or more servers and/or other computingresources, may perform data processing and other operations used toprovide on-demand services. Communication with the pods may be conductedvia pod switches 832 and 836. Components of the on-demand serviceenvironment may communicate with a database storage system 856 via adatabase firewall 848 and a database switch 852.

As shown in FIGS. 8A and 8B, accessing an on-demand service environmentmay involve communications transmitted among a variety of differenthardware and/or software components. Further, the on-demand serviceenvironment 800 is a simplified representation of an actual on-demandservice environment. For example, while only one or two devices of eachtype are shown in FIGS. 8A and 8B, some embodiments of an on-demandservice environment may include anywhere from one to many devices ofeach type. Also, the on-demand service environment need not include eachdevice shown in FIGS. 8A and 8B, or may include additional devices notshown in FIGS. 8A and 8B.

Moreover, one or more of the devices in the on-demand serviceenvironment 800 may be implemented on the same physical device or ondifferent hardware. Some devices may be implemented using hardware or acombination of hardware and software. Thus, terms such as “dataprocessing apparatus,” “machine,” “server” and “device” as used hereinare not limited to a single hardware device, but rather include anyhardware and software configured to provide the described functionality.

The cloud 804 is intended to refer to a data network or plurality ofdata networks, often including the Internet. Client machines located inthe cloud 804 may communicate with the on-demand service environment toaccess services provided by the on-demand service environment. Forexample, client machines may access the on-demand service environment toretrieve, store, edit, and/or process information.

In some embodiments, the edge routers 808 and 812 route packets betweenthe cloud 804 and other components of the on-demand service environment800. The edge routers 808 and 812 may employ the Border Gateway Protocol(BGP). The BGP is the core routing protocol of the Internet. The edgerouters 808 and 812 may maintain a table of IP networks or ‘prefixes’which designate network reachability among autonomous systems on theInternet.

In one or more embodiments, the firewall 816 may protect the innercomponents of the on-demand service environment 800 from Internettraffic. The firewall 816 may block, permit, or deny access to the innercomponents of the on-demand service environment 800 based upon a set ofrules and other criteria. The firewall 816 may act as one or more of apacket filter, an application gateway, a stateful filter, a proxyserver, or any other type of firewall.

In some embodiments, the core switches 820 and 824 are high-capacityswitches that transfer packets within the on-demand service environment800. The core switches 820 and 824 may be configured as network bridgesthat quickly route data between different components within theon-demand service environment. In some embodiments, the use of two ormore core switches 820 and 824 may provide redundancy and/or reducedlatency.

In some embodiments, the pods 840 and 844 may perform the core dataprocessing and service functions provided by the on-demand serviceenvironment. Each pod may include various types of hardware and/orsoftware computing resources. An example of the pod architecture isdiscussed in greater detail with reference to FIG. 8B.

In some embodiments, communication between the pods 840 and 844 may beconducted via the pod switches 832 and 836. The pod switches 832 and 836may facilitate communication between the pods 840 and 844 and clientmachines located in the cloud 804, for example via core switches 820 and824. Also, the pod switches 832 and 836 may facilitate communicationbetween the pods 840 and 844 and the database storage 856.

In some embodiments, the load balancer 828 may distribute workloadbetween the pods 840 and 844. Balancing the on-demand service requestsbetween the pods may assist in improving the use of resources,increasing throughput, reducing response times, and/or reducingoverhead. The load balancer 828 may include multilayer switches toanalyze and forward traffic.

In some embodiments, access to the database storage 856 may be guardedby a database firewall 848. The database firewall 848 may act as acomputer application firewall operating at the database applicationlayer of a protocol stack. The database firewall 848 may protect thedatabase storage 856 from application attacks such as structure querylanguage (SQL) injection, database rootkits, and unauthorizedinformation disclosure.

In some embodiments, the database firewall 848 may include a host usingone or more forms of reverse proxy services to proxy traffic beforepassing it to a gateway router. The database firewall 848 may inspectthe contents of database traffic and block certain content or databaserequests. The database firewall 848 may work on the SQL applicationlevel atop the TCP/IP stack, managing applications' connection to thedatabase or SQL management interfaces as well as intercepting andenforcing packets traveling to or from a database network or applicationinterface.

In some embodiments, communication with the database storage system 856may be conducted via the database switch 852. The multi-tenant databasesystem 856 may include more than one hardware and/or software componentsfor handling database queries. Accordingly, the database switch 852 maydirect database queries transmitted by other components of the on-demandservice environment (e.g., the pods 840 and 844) to the correctcomponents within the database storage system 856. In some embodiments,the database storage system 856 is an on-demand database system sharedby many different organizations. The on-demand database system mayemploy a multi-tenant approach, a virtualized approach, or any othertype of database approach. An on-demand database system is discussed ingreater detail with reference to FIGS. 9 and 10.

FIG. 8B shows a system diagram illustrating the architecture of the pod844, in accordance with one embodiment. The pod 844 may be used torender services to a user of the on-demand service environment 800. Insome embodiments, each pod may include a variety of servers and/or othersystems. The pod 844 includes one or more content batch servers 864,content search servers 868, query servers 872, file force servers 876,access control system (ACS) servers 880, batch servers 884, and appservers 888. Also, the pod 844 includes database instances 890, quickfile systems (QFS) 892, and indexers 894. In one or more embodiments,some or all communication between the servers in the pod 844 may betransmitted via the switch 836.

In some embodiments, the application servers 888 may include a hardwareand/or software framework dedicated to the execution of procedures(e.g., programs, routines, scripts) for supporting the construction ofapplications provided by the on-demand service environment 800 via thepod 844. Some such procedures may include operations for providing theservices described herein. The content batch servers 864 may requestsinternal to the pod. These requests may be long-running and/or not tiedto a particular customer. For example, the content batch servers 864 mayhandle requests related to log mining, cleanup work, and maintenancetasks.

The content search servers 868 may provide query and indexer functions.For example, the functions provided by the content search servers 868may allow users to search through content stored in the on-demandservice environment. The Fileforce servers 876 may manage requestsinformation stored in the Fileforce storage 878. The Fileforce storage878 may store information such as documents, images, and basic largeobjects (BLOBs). By managing requests for information using theFileforce servers 876, the image footprint on the database may bereduced.

The query servers 872 may be used to retrieve information from one ormore file systems. For example, the query system 872 may receiverequests for information from the app servers 888 and then transmitinformation queries to the NFS 896 located outside the pod. The pod 844may share a database instance 890 configured as a multi-tenantenvironment in which different organizations share access to the samedatabase. Additionally, services rendered by the pod 844 may requirevarious hardware and/or software resources. In some embodiments, the ACSservers 880 may control access to data, hardware resources, or softwareresources.

In some embodiments, the batch servers 884 may process batch jobs, whichare used to run tasks at specified times. Thus, the batch servers 884may transmit instructions to other servers, such as the app servers 888,to trigger the batch jobs. For some embodiments, the QFS 892 may be anopen source file system available from Sun Microsystems® of Santa Clara,Calif. The QFS may serve as a rapid-access file system for storing andaccessing information available within the pod 844. The QFS 892 maysupport some volume management capabilities, allowing many disks to begrouped together into a file system. File system metadata can be kept ona separate set of disks, which may be useful for streaming applicationswhere long disk seeks cannot be tolerated. Thus, the QFS system maycommunicate with one or more content search servers 868 and/or indexers894 to identify, retrieve, move, and/or update data stored in thenetwork file systems 896 and/or other storage systems.

In some embodiments, one or more query servers 872 may communicate withthe NFS 896 to retrieve and/or update information stored outside of thepod 844. The NFS 896 may allow servers located in the pod 844 to accessinformation to access files over a network in a manner similar to howlocal storage is accessed. In some embodiments, queries from the queryservers 822 may be transmitted to the NFS 896 via the load balancer 820,which may distribute resource requests over various resources availablein the on-demand service environment. The NFS 896 may also communicatewith the QFS 892 to update the information stored on the NFS 896 and/orto provide information to the QFS 892 for use by servers located withinthe pod 844.

In some embodiments, the pod may include one or more database instances890. The database instance 890 may transmit information to the QFS 892.When information is transmitted to the QFS, it may be available for useby servers within the pod 844 without requiring an additional databasecall. In some embodiments, database information may be transmitted tothe indexer 894. Indexer 894 may provide an index of informationavailable in the database 890 and/or QFS 892. The index information maybe provided to file force servers 876 and/or the QFS 892.

FIG. 9 shows a block diagram of an environment 910 wherein an on-demanddatabase service might be used, in accordance with some embodiments.Environment 910 includes an on-demand database service 916. User system912 may be any machine or system that is used by a user to access adatabase user system. For example, any of user systems 912 can be ahandheld computing system, a mobile phone, a laptop computer, a workstation, and/or a network of computing systems. As illustrated in FIGS.9 and 10, user systems 912 might interact via a network 914 with theon-demand database service 916.

An on-demand database service, such as system 916, is a database systemthat is made available to outside users that do not need to necessarilybe concerned with building and/or maintaining the database system, butinstead may be available for their use when the users need the databasesystem (e.g., on the demand of the users). Some on-demand databaseservices may store information from one or more tenants stored intotables of a common database image to form a multi-tenant database system(MTS). Accordingly, “on-demand database service 916” and “system 916”will be used interchangeably herein. A database image may include one ormore database objects. A relational database management system (RDBMS)or the equivalent may execute storage and retrieval of informationagainst the database object(s). Application platform 918 may be aframework that allows the applications of system 916 to run, such as thehardware and/or software, e.g., the operating system. In animplementation, on-demand database service 916 may include anapplication platform 918 that enables creation, managing and executingone or more applications developed by the provider of the on-demanddatabase service, users accessing the on-demand database service viauser systems 912, or third party application developers accessing theon-demand database service via user systems 912.

One arrangement for elements of system 916 is shown in FIG. 9, includinga network interface 920, application platform 918, tenant data storage922 for tenant data 923, system data storage 924 for system data 925accessible to system 916 and possibly multiple tenants, program code 926for implementing various functions of system 916, and a process space928 for executing MTS system processes and tenant-specific processes,such as running applications as part of an application hosting service.Additional processes that may execute on system 916 include databaseindexing processes.

The users of user systems 912 may differ in their respective capacities,and the capacity of a particular user system 912 might be entirelydetermined by permissions (permission levels) for the current user. Forexample, where a call center agent is using a particular user system 912to interact with system 916, the user system 912 has the capacitiesallotted to that call center agent. However, while an administrator isusing that user system to interact with system 916, that user system hasthe capacities allotted to that administrator. In systems with ahierarchical role model, users at one permission level may have accessto applications, data, and database information accessible by a lowerpermission level user, but may not have access to certain applications,database information, and data accessible by a user at a higherpermission level. Thus, different users may have different capabilitieswith regard to accessing and modifying application and databaseinformation, depending on a user's security or permission level.

Network 914 is any network or combination of networks of devices thatcommunicate with one another. For example, network 914 can be any one orany combination of a LAN (local area network), WAN (wide area network),telephone network, wireless network, point-to-point network, starnetwork, token ring network, hub network, or other appropriateconfiguration. As the most common type of computer network in currentuse is a TCP/IP (Transfer Control Protocol and Internet Protocol)network (e.g., the Internet), that network will be used in many of theexamples herein. However, it should be understood that the networks usedin some embodiments are not so limited, although TCP/IP is a frequentlyimplemented protocol.

User systems 912 might communicate with system 916 using TCP/IP and, ata higher network level, use other common Internet protocols tocommunicate, such as HTTP, FTP, AFS, WAP, etc. In an example where HTTPis used, user system 912 might include an HTTP client commonly referredto as a “browser” for sending and receiving HTTP messages to and from anHTTP server at system 916. Such an HTTP server might be implemented asthe sole network interface between system 916 and network 914, but othertechniques might be used as well or instead. In some embodiments, theinterface between system 916 and network 914 includes load sharingfunctionality, such as round-robin HTTP request distributors to balanceloads and distribute incoming HTTP requests evenly over a plurality ofservers. At least as for the users that are accessing that server, eachof the plurality of servers has access to the MTS' data; however, otheralternative configurations may be used instead.

In some embodiments, system 916, shown in FIG. 9, implements a web-basedcustomer relationship management (CRM) system. For example, in someembodiments, system 916 includes application servers configured toimplement and execute CRM software applications as well as providerelated data, code, forms, web pages and other information to and fromuser systems 912 and to store to, and retrieve from, a database systemrelated data, objects, and Webpage content. With a multi-tenant system,data for multiple tenants may be stored in the same physical databaseobject, however, tenant data typically is arranged so that data of onetenant is kept logically separate from that of other tenants so that onetenant does not have access to another tenant's data, unless such datais expressly shared. In certain embodiments, system 916 implementsapplications other than, or in addition to, a CRM application. Forexample, system 916 may provide tenant access to multiple hosted(standard and custom) applications. User (or third party developer)applications, which may or may not include CRM, may be supported by theapplication platform 918, which manages creation, storage of theapplications into one or more database objects and executing of theapplications in a virtual machine in the process space of the system916.

Each user system 912 could include a desktop personal computer,workstation, laptop, PDA, cell phone, or any wireless access protocol(WAP) enabled device or any other computing system capable ofinterfacing directly or indirectly to the Internet or other networkconnection. User system 912 typically runs an HTTP client, e.g., abrowsing program, such as Microsoft's Internet Explorer® browser,Mozilla's Firefox® browser, Opera's browser, or a WAP-enabled browser inthe case of a cell phone, PDA or other wireless device, or the like,allowing a user (e.g., subscriber of the multi-tenant database system)of user system 912 to access, process and view information, pages andapplications available to it from system 916 over network 914.

Each user system 912 also typically includes one or more user interfacedevices, such as a keyboard, a mouse, trackball, touch pad, touchscreen, pen or the like, for interacting with a graphical user interface(GUI) provided by the browser on a display (e.g., a monitor screen, LCDdisplay, etc.) in conjunction with pages, forms, applications and otherinformation provided by system 916 or other systems or servers. Forexample, the user interface device can be used to access data andapplications hosted by system 916, and to perform searches on storeddata, and otherwise allow a user to interact with various GUI pages thatmay be presented to a user. As discussed above, embodiments are suitablefor use with the Internet, which refers to a specific globalinternetwork of networks. However, it should be understood that othernetworks can be used instead of the Internet, such as an intranet, anextranet, a virtual private network (VPN), a non-TCP/IP based network,any LAN or WAN or the like.

According to some embodiments, each user system 912 and all of itscomponents are operator configurable using applications, such as abrowser, including computer code run using a central processing unitsuch as an Intel Pentium® processor or the like. Similarly, system 916(and additional instances of an MTS, where more than one is present) andall of their components might be operator configurable usingapplication(s) including computer code to run using a central processingunit such as processor system 917, which may include an Intel Pentium®processor or the like, and/or multiple processor units.

A computer program product implementation includes a machine-readablestorage medium (media) having instructions stored thereon/in which canbe used to program a computer to perform any of the processes of theembodiments described herein. Computer code for operating andconfiguring system 916 to intercommunicate and to process web pages,applications and other data and media content as described herein arepreferably downloaded and stored on a hard disk, but the entire programcode, or portions thereof, may also be stored in any other volatile ornon-volatile memory medium or device, such as a ROM or RAM, or providedon any media capable of storing program code, such as any type ofrotating media including floppy disks, optical discs, digital versatiledisk (DVD), compact disk (CD), microdrive, and magneto-optical disks,and magnetic or optical cards, nanosystems (including molecular memoryICs), or any type of media or device suitable for storing instructionsand/or data. Additionally, the entire program code, or portions thereof,may be transmitted and downloaded from a software source over atransmission medium, e.g., over the Internet, or from another server, ortransmitted over any other conventional network connection (e.g.,extranet, VPN, LAN, etc.) using any communication medium and protocols(e.g., TCP/IP, HTTP, HTTPS, Ethernet, etc.). It will also be appreciatedthat computer code for implementing embodiments can be implemented inany programming language that can be executed on a client system and/orserver or server system such as, for example, C, C++, HTML, any othermarkup language, Java™, JavaScript®, ActiveX®, any other scriptinglanguage, such as VBScript, and many other programming languages as arewell known may be used. (Java™ is a trademark of Sun Microsystems®,Inc.).

According to some embodiments, each system 916 is configured to provideweb pages, forms, applications, data and media content to user (client)systems 912 to support the access by user systems 912 as tenants ofsystem 916. As such, system 916 provides security mechanisms to keepeach tenant's data separate unless the data is shared. If more than oneMTS is used, they may be located in close proximity to one another(e.g., in a server farm located in a single building or campus), or theymay be distributed at locations remote from one another (e.g., one ormore servers located in city A and one or more servers located in cityB). As used herein, each MTS could include logically and/or physicallyconnected servers distributed locally or across one or more geographiclocations. Additionally, the term “server” is meant to include acomputing system, including processing hardware and process space(s),and an associated storage system and database application (e.g., OODBMSor RDBMS) as is well known in the art.

It should also be understood that “server system” and “server” are oftenused interchangeably herein. Similarly, the database object describedherein can be implemented as single databases, a distributed database, acollection of distributed databases, a database with redundant online oroffline backups or other redundancies, etc., and might include adistributed database or storage network and associated processingintelligence.

FIG. 10 also shows a block diagram of environment 910 furtherillustrating system 916 and various interconnections, in accordance withsome embodiments. FIG. 10 shows that user system 912 may includeprocessor system 912A, memory system 912B, input system 912C, and outputsystem 912D. FIG. 10 shows network 914 and system 916. FIG. 10 alsoshows that system 916 may include tenant data storage 922, tenant data923, system data storage 924, system data 925, User Interface (UI) 1030,Application Program Interface (API) 1032, PL/SOQL 1034, save routines1036, application setup mechanism 1038, applications servers10001-1000N, system process space 1002, tenant process spaces 1004,tenant management process space 1010, tenant storage area 1012, userstorage 1014, and application metadata 1016. In other embodiments,environment 910 may not have the same elements as those listed aboveand/or may have other elements instead of, or in addition to, thoselisted above.

User system 912, network 914, system 916, tenant data storage 922, andsystem data storage 924 were discussed above in FIG. 9. Regarding usersystem 912, processor system 912A may be any combination of processors.Memory system 912B may be any combination of one or more memory devices,short term, and/or long term memory. Input system 912C may be anycombination of input devices, such as keyboards, mice, trackballs,scanners, cameras, and/or interfaces to networks. Output system 912D maybe any combination of output devices, such as monitors, printers, and/orinterfaces to networks. As shown by FIG. 10, system 916 may include anetwork interface 920 (of FIG. 9) implemented as a set of HTTPapplication servers 1000, an application platform 918, tenant datastorage 922, and system data storage 924. Also shown is system processspace 1002, including individual tenant process spaces 1004 and a tenantmanagement process space 1010. Each application server 1000 may beconfigured to tenant data storage 922 and the tenant data 923 therein,and system data storage 924 and the system data 925 therein to serverequests of user systems 912. The tenant data 923 might be divided intoindividual tenant storage areas 1012, which can be either a physicalarrangement and/or a logical arrangement of data. Within each tenantstorage area 1012, user storage 1014 and application metadata 1016 mightbe similarly allocated for each user. For example, a copy of a user'smost recently used (MRU) items might be stored to user storage 1014.Similarly, a copy of MRU items for an entire organization that is atenant might be stored to tenant storage area 1012. A UI 1030 provides auser interface and an API 1032 provides an application programmerinterface to system 916 resident processes to users and/or developers atuser systems 912. The tenant data and the system data may be stored invarious databases, such as Oracle™ databases.

Application platform 918 includes an application setup mechanism 1038that supports application developers' creation and management ofapplications, which may be saved as metadata into tenant data storage922 by save routines 1036 for execution by subscribers as tenant processspaces 1004 managed by tenant management process 1010 for example.Invocations to such applications may be coded using PL/SOQL 34 thatprovides a programming language style interface extension to API 1032. Adetailed description of some PL/SOQL language embodiments is discussedin commonly assigned U.S. Pat. No. 7,730,478, titled METHOD AND SYSTEMFOR ALLOWING ACCESS TO DEVELOPED APPLICATIONS VIA A MULTI-TENANTON-DEMAND DATABASE SERVICE, by Craig Weissman, filed Sep. 21, 4007,which is hereby incorporated by reference in its entirety and for allpurposes. Invocations to applications may be detected by systemprocesses, which manage retrieving application metadata 1016 for thesubscriber making the invocation and executing the metadata as anapplication in a virtual machine.

Each application server 1000 may be communicably coupled to databasesystems, e.g., having access to system data 925 and tenant data 923, viaa different network connection. For example, one application server10001 might be coupled via the network 914 (e.g., the Internet), anotherapplication server 1000N-1 might be coupled via a direct network link,and another application server 1000N might be coupled by yet a differentnetwork connection. Transfer Control Protocol and Internet Protocol(TCP/IP) are typical protocols for communicating between applicationservers 1000 and the database system. However, other transport protocolsmay be used to optimize the system depending on the network interconnectused.

In certain embodiments, each application server 1000 is configured tohandle requests for any user associated with any organization that is atenant. Because it is desirable to be able to add and remove applicationservers from the server pool at any time for any reason, there ispreferably no server affinity for a user and/or organization to aspecific application server 1000. In some embodiments, therefore, aninterface system implementing a load balancing function (e.g., an F5Big-IP load balancer) is communicably coupled between the applicationservers 1000 and the user systems 912 to distribute requests to theapplication servers 1000. In some embodiments, the load balancer uses aleast connections algorithm to route user requests to the applicationservers 1000. Other examples of load balancing algorithms, such as roundrobin and observed response time, also can be used. For example, incertain embodiments, three consecutive requests from the same user couldhit three different application servers 1000, and three requests fromdifferent users could hit the same application server 1000. In thismanner, system 916 is multi-tenant, wherein system 916 handles storageof, and access to, different objects, data and applications acrossdisparate users and organizations.

As an example of storage, one tenant might be a company that employs asales force where each call center agent uses system 916 to manage theirsales process. Thus, a user might maintain contact data, leads data,customer follow-up data, performance data, goals and progress data,etc., all applicable to that user's personal sales process (e.g., intenant data storage 922). In an example of a MTS arrangement, since allof the data and the applications to access, view, modify, report,transmit, calculate, etc., can be maintained and accessed by a usersystem having nothing more than network access, the user can manage hisor her sales efforts and cycles from any of many different user systems.For example, if a call center agent is visiting a customer and thecustomer has Internet access in their lobby, the call center agent canobtain critical updates as to that customer while waiting for thecustomer to arrive in the lobby.

While each user's data might be separate from other users' dataregardless of the employers of each user, some data might beorganization-wide data shared or accessible by a plurality of users orall of the users for a given organization that is a tenant. Thus, theremight be some data structures managed by system 916 that are allocatedat the tenant level while other data structures might be managed at theuser level. Because an MTS might support multiple tenants includingpossible competitors, the MTS should have security protocols that keepdata, applications, and application use separate. Also, because manytenants may opt for access to an MTS rather than maintain their ownsystem, redundancy, up-time, and backup are additional functions thatmay be implemented in the MTS. In addition to user-specific data andtenant specific data, system 916 might also maintain system level datausable by multiple tenants or other data. Such system level data mightinclude industry reports, news, postings, and the like that are sharableamong tenants.

In certain embodiments, user systems 912 (which may be clientmachines/systems) communicate with application servers 1000 to requestand update system-level and tenant-level data from system 916 that mayrequire sending one or more queries to tenant data storage 922 and/orsystem data storage 924. System 916 (e.g., an application server 1000 insystem 916) automatically generates one or more SQL statements (e.g.,SQL queries) that are designed to access the desired information. Systemdata storage 924 may generate query plans to access the requested datafrom the database.

Each database can generally be viewed as a collection of objects, suchas a set of logical tables, containing data fitted into predefinedcategories. A “table” is one representation of a data object, and may beused herein to simplify the conceptual description of objects and customobjects according to some embodiments. It should be understood that“table” and “object” may be used interchangeably herein. Each tablegenerally contains one or more data categories logically arranged ascolumns or fields in a viewable schema. Each row or record of a tablecontains an instance of data for each category defined by the fields.For example, a CRM database may include a table that describes acustomer with fields for basic contact information such as name,address, phone number, fax number, etc. Another table might describe apurchase order, including fields for information such as customer,product, sale price, date, etc. In some multi-tenant database systems,standard entity tables might be provided for use by all tenants. For CRMdatabase applications, such standard entities might include tables foraccount, contact, lead, and opportunity data, each containingpre-defined fields. It should be understood that the word “entity” mayalso be used interchangeably herein with “object” and “table”.

In some multi-tenant database systems, tenants may be allowed to createand store custom objects, or they may be allowed to customize standardentities or objects, for example by creating custom fields for standardobjects, including custom index fields. U.S. Pat. No. 7,779,039, titledCUSTOM ENTITIES AND FIELDS IN A MULTI-TENANT DATABASE SYSTEM, byWeissman, et al., and which is hereby incorporated by reference in itsentirety and for all purposes, teaches systems and methods for creatingcustom objects as well as customizing standard objects in a multi-tenantdatabase system. In some embodiments, for example, all custom entitydata rows are stored in a single multi-tenant physical table, which maycontain multiple logical tables per organization. In some embodiments,multiple “tables” for a single customer may actually be stored in onelarge table and/or in the same table as the data of other customers.

These and other aspects of the disclosure may be implemented by varioustypes of hardware, software, firmware, etc. For example, some featuresof the disclosure may be implemented, at least in part, bymachine-program product that include program instructions, stateinformation, etc., for performing various operations described herein.Examples of program instructions include both machine code, such asproduced by a compiler, and files containing higher-level code that maybe executed by the computer using an interpreter. Examples ofmachine-program product include, but are not limited to, magnetic mediasuch as hard disks, floppy disks, and magnetic tape; optical media suchas CD-ROM disks; magneto-optical media; and hardware devices that arespecially configured to store and perform program instructions, such asread-only memory devices (“ROM”) and random access memory (“RAM”).

While one or more embodiments and techniques are described withreference to an implementation in which a service cloud console isimplemented in a system having an application server providing a frontend for an on-demand database service capable of supporting multipletenants, the one or more embodiments and techniques are not limited tomulti-tenant databases nor deployment on application servers.Embodiments may be practiced using other database architectures, i.e.,ORACLE®, DB2® by IBM and the like without departing from the scope ofthe embodiments claimed.

Any of the above embodiments may be used alone or together with oneanother in any combination. Although various embodiments may have beenmotivated by various deficiencies with the prior art, which may bediscussed or alluded to in one or more places in the specification, theembodiments do not necessarily address any of these deficiencies. Inother words, different embodiments may address different deficienciesthat may be discussed in the specification. Some embodiments may onlypartially address some deficiencies or just one deficiency that may bediscussed in the specification, and some embodiments may not address anyof these deficiencies.

While various embodiments have been described herein, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of the present applicationshould not be limited by any of the embodiments described herein, butshould be defined only in accordance with the following andlater-submitted claims and their equivalents.

What is claimed is:
 1. A method comprising: generating by a firstrequester of a first group of requesters, a request to be transmitted toa first server computing system; accessing, by the first requester ofthe first group of requesters, an indicator stored in a memory deviceassociated with a second server computing system to verify theavailability of first server computing system to receive requests, theindicator being set or reset at least based on a response received fromthe first server computing system, each requester of the first group ofrequesters being configured to access the indicator prior totransmitting a request to a second server computing system; delayingtransmission of the request from the first requester to the first servercomputing system in response to an indication from the indicator thatthe first server computing system is not ready to receive requests. 2.The method of claim 1, further comprising accessing, by the firstrequester, the indicator after a delay period to determine whether thesecond server computing system is ready to receive the request.
 3. Themethod of claim 2, further comprising transmitting, by the firstrequester, the request to the second server computing system based onthe indicator indicating that the second server computing system isready.
 4. The method of claim 3, wherein the indicator is set when thesecond server computing system is not ready and reset when the secondserver computing system is ready, wherein the indicator is automaticallyreset after expiration of a reset period, and wherein the delay periodis shorter than the reset period.
 5. The method of claim 4, wherein theresponse received from the second server computing system is configuredto include in a response header information to indicate whether thesecond server computing system ready to accept requests from therequesters in the first group of requesters.
 6. The method of claim 5,wherein the first requester is configured to set the indicator based onthe response from the second server computing system indicating that thesecond server computing system is not ready.
 7. The method of claim 6,wherein the first requester is configured to reset the indicator basedon the response from the second server computing system indicating thatthe second server computing system is ready.
 8. The method of claim 7,wherein the requesters in the first group of the requesters areassociated with a first type of service, wherein requesters in a secondgroup of requesters are associated with a second type of service, andwherein a request generated by a second requester in the second group ofrequesters is configured to be transmitted to the second servercomputing system without having to access the indicator.
 9. The methodof claim 8, wherein the second type of service is of higher prioritythan the first type of service.
 10. An apparatus comprising: one or moreprocessors; and a non-transitory computer readable medium storing aplurality of instructions, which when executed, cause the one or moreprocessors to: generate by a first requester of a first group ofrequesters, a request to be transmitted to a first server computingsystem; access, by the first requester of the first group of requesters,an indicator stored in a memory device associated with a second servercomputing system to verify the availability of first server computingsystem to receive requests, the indicator being set or reset at leastbased on a response received from the first server computing system,each requester of the first group of requesters being configured toaccess the indicator prior to transmitting a request to a second servercomputing system; delay transmission of the request from the firstrequester to the first server computing system in response to anindication from the indicator that the first server computing system isnot ready to receive requests.
 11. The apparatus of claim 10, furthercomprising instructions to access the indicator after a delay period todetermine whether the second server computing system is ready to receivethe request.
 12. The apparatus of claim 11, further comprisinginstructions to transmit the request to the second server computingsystem based on the indicator indicating that the second servercomputing system is ready.
 13. The apparatus of claim 12, wherein theindicator is set when the second server computing system is not readyand reset when the second server computing system is ready, wherein theindicator is automatically reset after expiration of a reset period, andwherein the delay period is shorter than the reset period.
 14. Theapparatus of claim 13, wherein the response received from the secondserver computing system is configured to include in a response headerinformation to indicate whether the second server computing system readyto accept requests from the requesters in the first group of requesters.15. The apparatus of claim 14, wherein the first requester is configuredto set the indicator based on the response from the second servercomputing system indicating that the second server computing system isnot ready.
 16. The apparatus of claim 15, wherein the first requester isconfigured to reset the indicator based on the response from the secondserver computing system indicating that the second server computingsystem is ready.
 17. The apparatus of claim 16, wherein the requestersin the first group of the requesters are associated with a first type ofservice, wherein requesters in a second group of requesters areassociated with a second type of service, and wherein a requestgenerated by a second requester in the second group of requesters isconfigured to be transmitted to the second server computing systemwithout having to access the indicator.
 18. The apparatus of claim 17,wherein the second type of service is of higher priority than the firsttype of service.
 19. A computer program product comprisingcomputer-readable program code to be executed by one or more processorswhen retrieved from a non-transitory computer-readable medium, theprogram code including instructions to: generate by a first requester ofa first group of requesters, a request to be transmitted to a firstserver computing system; access, by the first requester of the firstgroup of requesters, an indicator stored in a memory device associatedwith a second server computing system to verify the availability offirst server computing system to receive requests, the indicator beingset or reset at least based on a response received from the first servercomputing system, each requester of the first group of requesters beingconfigured to access the indicator prior to transmitting a request to asecond server computing system; delay transmission of the request fromthe first requester to the first server computing system in response toan indication from the indicator that the first server computing systemis not ready to receive requests.
 20. The computer program product ofclaim 19, further comprising instructions to access the indicator aftera delay period to determine whether the second server computing systemis ready to receive the request.
 21. The computer program product ofclaim 20, further comprising instructions to transmit the request to thesecond server computing system based on the indicator indicating thatthe second server computing system is ready.
 22. The computer programproduct of claim 21, wherein the indicator is set when the second servercomputing system is not ready and reset when the second server computingsystem is ready, wherein the indicator is automatically reset afterexpiration of a reset period, and wherein the delay period is shorterthan the reset period.
 23. The computer program product of claim 22,wherein the response received from the second server computing system isconfigured to include in a response header information to indicatewhether the second server computing system ready to accept requests fromthe requesters in the first group of requesters.
 24. The computerprogram product of claim 23, wherein the first requester is configuredto set the indicator based on the response from the second servercomputing system indicating that the second server computing system isnot ready.
 25. The computer program product of claim 24, wherein thefirst requester is configured to reset the indicator based on theresponse from the second server computing system indicating that thesecond server computing system is ready.
 26. The computer programproduct of claim 25, wherein the requesters in the first group of therequesters are associated with a first type of service, whereinrequesters in a second group of requesters are associated with a secondtype of service, wherein a request generated by a second requester inthe second group of requesters is configured to be transmitted to thesecond server computing system without having to access the indicator,and wherein the second type of service is of higher priority than thefirst type of service.